One of the lessons that I am leaning towards for China is that Russia is completely useless and the idea that they can contribute any useful knowledge (scientific, political, military theory, etc) is nonsensical. Personally I think China should drop Russia like a bad habit.
The war in Ukraine has been a disaster for them militarily, politically and economically. This is absolutely not the way in which China would want any action in Taiwan to go. Period. So it's time to realize that outside of Soviet legacy, Russia is incapable of being a true military or economic power. As time goes on, this will only become more apparent and the disparity between China and Russia will grow. The reality is that Russia will have to come to China for assistance in the future, especially after this Ukraine debacle winds down (likely in a humiliating way for Russia).
So yeah, if China wants to continue a strategic relationship with Russia it must be on Chinese terms. Meaning that China will determine if Russia can invade a country and weather those actions are in China's best interest.
I disagree with the assertion that Russia is destined to be a junior partner in the Sino-Russian strategic partnership. There is a strong interest for China to continue to work with Russia, comprehensively and indefinitely. Ever since the end of the Cold War, Chinese leaders have held the view that the support of Russia is pivotal in shifting to a multipolar world. Russia may have lost the potential to sustain a bipolar competition with the United States, but it continues to hold many cards that are so important as to place them in a kingmaker position.
The Russian economy may appear to be small when viewed as an aggregated nominal GDP, but this is totally misleading when it comes to representing its capacity for supporting a military and exerting hard power. The nominal GDP of Russia is only around the level of South Korea, because of the enormous fall in the ruble exchange rate since 2014 and the low nominal wages in Russia. However, the Russian economy in purchasing power parity terms (PPP) is larger than France or UK, and on par with Germany. Most geopolitical analysts will agree that, when it comes to assessing the potential for an economy to build a military, PPP is a far better measure than nominal USD GDP.
Furthermore, the composition of one's GDP matters in terms of hard power implications - this is often overlooked by Western economists. The nominal GDP of South Korea may be large for its population, and the United States obviously has a massive economy, but what exactly are these economies composed of? The truth is they are heavily service, entertainment, and finance based economies, at least relative to the industrial and resource based economies of China and Russia. South Korea has great K-pop entertainment and e-sports. The US is really good at making Justin Bieber CDs, Angelina Jolie movies, pornography, consultancy for Wall Street, political adverts, so on and so forth, and these goods are very expensive and therefore contribute greatly to GDP. In contrast, Russia produces base commodities like oil, natural gas, grain, aluminium and titanium, along with a sizable industrial, shipbuilding and aerospace sector, while Russia exports very little entertainment goods. Tell me, which country will be better at transforming their economic power into hard military power? (It's Russia)
People who dismiss the military potential of the Russia economy often ignores these two key nuances - PPP measure and composition, and they often get a misleading picture.
The West has burned all bridges with Russia and created in that country a multi-generational enemy, and for no good reason. China should not pass on this opportunity. China has always been concerned about the potential for a distant US blockade in the event of a conflict. While China may be well-placed to hold its own militarily in the Western Pacific, it can do very little to lift a distant US lockade, for example in the Indian Ocean. This would disrupt the flow of natural resources that are needed to sustain the Chinese war effort. However, with the support of Russia, a US-led naval blockade would lose its teeth. Russia can fill the gap in Chinese demand for raw materials that are not met by domestic production, thereby sustaining the Chinese military industrial complex under a blockade.
So let me tell you something: Russia is not China's burden. Russia still holds a considerable reservoir of hard power that often gets missed by surface-level analysis. The enmity of Russia would hinder China's capability to wage a long war, while the support of Russia is critical for moving towards multipolarity. The West has chosen to burn their Russia card as a result of incompetent foreign policy, and this will be their undoing.